HOUSTON—Overweight or obesity during early adulthood is associated with a greater risk of pancreatic cancer and a younger age of disease onset. Obesity at an older age was associated with a lower overall survival in patients with pancreatic cancer.
The study, conducted at the University of Texas M.D. Anderson Cancer Center and published in the Journal of the American Medical Association (JAMA. 2009;301(24):2553-2562), revealed that individuals who were overweight (a BMI of 25-29.9) from the ages of 14 to 39 years (highest odds ratio [OR], 1.67; 95% confidence interval [CI], 1.20-2.34) or obese (a BMI 30) from the ages of 20 to 49 years (highest OR, 2.58; 95% CI, 1.70-3.90) had an associated increased risk of pancreatic cancer, independent of diabetes status. The association was stronger in men (adjusted OR, 1.80; 95% CI, 1.45-2.23) by mean BMI from the ages of 14 to 59 years than in women (adjusted OR, 1.32; 95% CI, 1.02-1.70) and in ever smokers (adjusted OR, 1.75; 95% CI, 1.37-2.22) than in never smokers (adjusted OR, 1.46; 95% CI, 1.16-1.84).
The population-attributable risk percentage of pancreatic cancer based on the mean BMI from the ages of 14 to 59 years was 10.3% for never smokers and 21.3% for ever smokers. Individuals who were overweight or obese from the ages of 20 to 49 years had an earlier onset of pancreatic cancer by 2 to 6 years (median age of onset was 64 years for patients with normal weight, 61 years for overweight patients [P = .02], and 59 years for obese patients [P < .001]). Compared with those with normal body weight and after adjusting for all clinical factors, individuals who were overweight or obese from the ages of 30 to 79 years or in the year prior to recruitment had reduced overall survival of pancreatic cancer regardless of disease stage and tumor resection status (overweight patients: hazard ratio, 1.26 [95% CI, 0.94-1.69], P = .04; obese patients: hazard ratio, 1.86 [95% CI, 1.35-2.56], P < .001).